Hybrid Optothermal-Magnetic Mobile Microgripper for In-Liquid Micromanipulation

In this letter, we propose a mobile microgripper actuated using laser optothermal and magnetic actuation in liquid environments. This hybrid actuation scheme allows the full decoupling between the in-plane positioning of the mobile microgripper and the actuation of its gripping mechanism, which reduces the control complexity of such microgrippers. The developed mobile microgripper with the dimensions of 1500 $\times 700\times$ 250 μ $\mathrm{m^{3}}$ can realize an open and close gripping motion of 35 μm, a magnetic positioning accuracy of 6 μm for translation over an area of 1 × 1 mm and 2 $^{\circ }$ for rotation, and a laser steering accuracy of 25 μm. Finally, the mobile microgripper is used to control the position of a microbead inside a liquid environment. Our work provides a proof of concept of laser optothermal-magnetic hybrid actuation, which has the potential to enhance the deployment of microtools in biomedical applications including cell manipulation and lab-on-chip devices.